Yes. All my life I've been given 'the look.' Every job I've had though has given me a great reference on leaving.
My weight was in the 20's and I tried to counter balance people's prejudice by dressing well, nice hair, sunny personality etc and to some extent that worked.
I've since shocked myself that I'm fatist. I always look at every candidate and wonder whether they can do the job from a physical point of view. A large person walking 3 flights of stairs to the office? sounds doable but that person will need to use the stairs to get lunches, coffee, greet people, post office trips...the job would take longer.
A large childminder? I never see large people running after kids, so would they be able to keep up?
Sometimes it really doesn't matter and that is when it is prejudice but there will always be reasons why you don't get the job.
I used to spend a lot of my time trying not to look lazy and tired.
As for self discipline, getting out of bed at 3 times the weight of a normal person - you don't get much better self discipline than that.
The poster above Sarasue has clearly never been overweight and should probably stick to posting on fluffy stuff. Please don't come back to say you struggled to lose 5lbs and you went to gym everyday until it came off blah blah blah. Your comments are nasty.